The invention concerns an adhesive closure part, in particular, for the foaming of upholstery for vehicle seats during their production, with adhesive elements on one side for linkage with corresponding adhesive elements of another adhesive closure part, by formation of an adhesive closure, and with a linking device on the other side of the adhesive closure part for the production of a linkage with the pertinent foam material.
Such adhesive closure parts are known from EP 0 612 485, wherein the adhesive closure part is placed in a foaming mold in such a way that the linking device in the form of loop elements on the backside of the adhesive closure part comes into contact with the pertinent foam material, so as to produce a firm linkage with it. The opposite front side of the adhesive closure part has adhesive elements in the form of linking hooks, adhesives heads, or the like, which are protected from the penetration of foam material, for example, as described in the European document, in that they are surrounded on their entire surface by an uncrosslinked thermoplastic. If after the foaming process in the mold and the removal of the foamed part, the cover is removed, the adhesive elements are free and can later be joined with adhesive elements of another adhesive closure part, for example, in the form of a loop strip, with the formation of a common adhesive closure.
In this way, it is possible to affix, for example, upholstery covering materials to the foamed upholstery parts of a vehicle seat or an airplane seat or to join rotating components, for example, in the form of grinding wheels to tool holding fixtures, in conventional grinders and apparatuses. The aforementioned foam material can definitely be highly fluid, as a function of the object to be formed and can have viscosities which are in the range of water or below. It has become evident that when using looping and noose-like material as a fastener or even when using a nappy cloth or the like, the nooses, which are in fact open, are not completely penetrated by the foam material, but rather form a kind of barrier for it which inhibits the penetration of the foam material. In the subsequent hardening or baking process for the foam material, there are voids, that is, gaslike hollow occlusions, which work against a firm bonding between the adhesive closure part and the foam material at the transition sites between the looping material and the foam. As a result of such a reduced strength of the bonding between the adhesive closure part and foam material, there is a loosening of the bonding with continuous stresses, and the adhesive closure part tears out of the foam material, which can lead to the lack of usefulness of the entire component, for example, in the form of a vehicle seat or a grinding disk holding fixture.
On the basis of this state of the art, the goal of the invention is to further improve an adhesive closure part of the type mentioned in the beginning in such a way that a reliable and very strong bonding between the adhesive closure part and the foam material used can be attained. Such a goal can be attained by an adhesive closure part with the features of Claim 1.
Due to the fact that in accordance with the characterizing section, the bonding agent is made of an adhesive base, applied on the other side of the adhesive closure part, a kind of primer layer is formed on the adhesive closure part, and this layer enters into a very strong bonding with the pertinent foam material and thus guarantees a reliable, hard-to-undo bonding between the adhesive closure part and the later foam body.
To a specialist in the field of adhesive closures and foaming technology, it is surprising that by the application of the adhesive base on the adhesive closure part, wherein a very thin layer ( less than 0.1 mm) is formed, one attains a better bonding to the foam material than by means of a noose-like fabric, which requires a certain expenditure of effort and thus is cost-intensive and in which the loops spatially penetrate and push forward far into the foam material. Instead of a mechanical hooking of looped or noose-like material with the foam, an adhesion to the foam material is produced by means of the individually used adhesive base and the primer layer during its production with heat and pressure, which leads to higher strength values with the desired bonding.
If the adhesive closure part under discussion is made of a polyamide material, then resorcinol, polyurethane, and post-crosslinkable polymers are used as the adhesive base. If the adhesive closure or the adhesive closure part is made of polyolefin, then polyurethane, or polymers which are post-crosslinkable are preferably used as the adhesive or primer.
If in a particularly preferred embodiment, the individual adhesive base is provided with a ferromagnetic material, then the adhesive closure part can be placed in the metal foam mold in a detachable way and is positioned in the placed site within the mold via magnetic forces. In this way, the placing of the strip-like adhesive closure part can be attained in the foaming molds in a particularly inexpensive manner.